Cftransaction & mySQL table locking

I have a series of mySQL query updates within a cftransaction driven by Flash code and I need to lock the relevant tables to prevent other users from updating whilst this transaction is in progress. So, prior to the cftransaction statement, I execute a query:

LOCK TABLE tableA WRITE, tableB WRITE, ...etc

and following the /cftransaction, and other query:

UNLOCK TABLES.

it works fine. ne problem is that there seem to be no way to test whether I have actually obtained these locks. As a test, I used the query browser to lock tableA and then I executed my Flash transaction. On screen it didn't update and eventually traced:

Error opening URL "http://devel:8500/flashservices/gateway/"

Checking the database, all tables EXCEPT tableA were updated. Not what I would have hoped. So, how can I achieve my objective - any thoughts?